Could a ‘Death Star’ Really Destroy a Planet?

[/caption]Countless Sci-Fi fans vividly remember the famous scene in Star Wars in which the Death Star obliterates the planet Alderaan.

Mirroring many late night caffeine-fueled arguments among Sci-Fi fans, a University of Leicester researcher asks the question:

Could a small moon-sized battle station generate enough energy to destroy an Earth-sized planet?

A paper by David Boulderston (University of Leicester) sets out to answer that very question. First, for the uninitiated, just what the heck is a Death Star?

According to Star Wars lore, the DS-1 Orbital Battle Station, or Death Star, is a moon-sized battle station designed to spread fear throughout the galaxy. The image above shows the Death Star as it appeared in Star Wars Episode IV: A New Hope (1977). The Death Star’s main weapon is depicted as a superlaser capable of destroying planets with a single blast.

Boulderston claims that it is possible to estimate how much energy the Death Star would need in order to destroy a planet with its superlaser. There are a number of assumptions made, however, in order to come up with the energy requirement.

For starters, Boulderston assumed that Alderaan did not have any sort of planetary “deflector” shield. A second assumption is that the planet is a solid body of uniform density – essentially ignoring the complex interior of planets, due to lack of information on Alderaan itself. Using the idealized sphere model based on Earth’s mass and diameter, it was possible to determine the gravitational binding energy of Alderaan, using a simple equation of:

U= 3GMp2
——
5Rp

Where G is the Gravitational Constant (6.673×10-11), Mp is planet mass, and Rp is the planet’s radius. Using Earth’s mass and radius, the required energy comes out to 2.25 x 1032 Joules. Using Jupiter’s data, the energy required goes up to 2 x 1036 Joules.

Boulderston asserts that (according to Star Wars lore) the Death Star is powered by a ‘hypermatter’ reactor, possessing the energy output of several main-sequence stars. Given that the power output of our Sun is about 3 x 1026 Joules per second, it’s a reasonable assumption the Death Star’s reactor could power the superlaser.

Despite using a simplified model of a planet, Boulderstone states the simplified model is reasonable to use since the Death Star’s main power reactor has the energy output equal to several main-sequence stars. Even if Earth’s exact composition were used in the equation above, the required energy to destroy a planet would only be affected by a few orders of magnitude – well within the Death Star’s power budget.

Boulderstone reiterated that the energy required to destroy a Jupiter-sized planet would put considerable strain on the Death Star. To destroy a planet like Jupiter, all power from essential systems and life support (no re-routing from the auxiliary EPS conduits – that’s a Star Trek hack!) would be required, which is not necessarily possible.

Boulderstone’s conclusion is that the Death Star could indeed destroy Earth-like planets, given its main power source. While the Death Star could destroy an Earth-sized planet, a Jupiter-sized planet would be a tough challenge, and the Galactic Empire would need to resort to using a Suncrusher to destroy stars.

Assuming a fairly liberal value of “several” to be 100, that’s still something like 2 hours of beaming to blow up Alderaan – assuming no energy loss over that time! And never mind Jupiter – that’s years…

According to Star Wars lore, the Death Star could only fire a planet destroying beam once per day. If you remember in “Return of the Jedi”, the second Death Star was able to fire ship destroying blasts pretty rapidly.

You MUST read this classic article by Sam Hughes: How to destroy the Earth; which explains in more informal language the difficulty of this task. Classic quote:

“The Earth is built to last. It is a 4,550,000,000-year-old, 5,973,600,000,000,000,000,000-tonne ball of iron. It has taken more devastating asteroid hits in its lifetime than you’ve had hot dinners, and lo, it still orbits merrily. So my first piece of advice to you, dear would-be Earth-destroyer, is: do NOT think this will be easy.”

They could be changing the Gravitational Constant G Constant (6.673×10^-11>) using the force by the “dark side.” After all Jedi can raise heavy objects and toss them about as if they were nothing.
Even the beam might have a multi-dimensional manifestation of the hyperspace somehow channelling its energies into real space.
A third option is an exploding space bomb or “quantum bomb”, where somehow twisted space is unravelled into the universe greatly expanding near the planet causing it to be torn apart.
Fourth, an artificial supernova by damaging the interactions in atoms of either the strong or the weak force
Yet, using normal physics, I agree, it does not seem possible.

They could even fall back to their original, pre-Death Star, methods: send a squadron of Victory-class Star Destroyers (the one you see trying to stop the Millennium Falcon from leaving Tatooine) to glass the surface of the planet.

I never quite got how point source outputs from the edges of the parabolic dish somehow became linearly inverted towards the dish’s focal point – and then somehow all that energy was concentrated into a straight beam. I mean, huh?

If they had put the transmitter at the dish’s focal point to create an attentuating wave of energy directed at the dish’s surface so that the energy was reflected and concentrated into a collimated beam – that would have been one kick-ass bit of science fiction.

Given that the gravitational binding energy of the Earth is 10^{32} joules and that the Death Star blasted Alderaan in about a second that much energy must be imparted to it. By E = mc^2 this means 10^{32}j/9×10^{16}m^/s^2 ~ 10^{16}kg of mass would have to be converted into energy. This is about 10 trillion tons. If this mass is in ordinary matter form (not a quantum black hole etc) at 10g/cm^3 the volume of this mass would be 10^{18}cm^3 or 10^6cm in radius or 10^4m = 10km. That is a pretty hefty bit of matter to convert to energy that quickly and hurl at a planet.

Of course it would require far less energy to drag a Ceres mass asteroid into the planet. That would clean the clock out of the planet and I doubt any civilization would survive it.

The biggest reason for using the Death Star to destroy a planet is that it would send a message to any other systems that would be thinking about joining the rebellion. Sure, there might be more efficient ways of doing it, but being able to say “obey or get Death Starred” is a powerful tool in oppression.

“Fear will keep them in line! Fear of this battle station.”

However, they were overconfident and did not think the Rebellion would have the balls to attack it directly.

Of course the whole Star Wars series is a classic mythic narrative. The characters Lucas scripted have that somewhat 2-d nature common of characters in mythology, whether that be Greek, Keltic or Norse mythology, the Mahabharata, the Bible and so forth. It is classic good vs evil narrative with characters put to various tests and with a mystical power (God, YHVH, The Force, Vishnu etc) operating behind it all. The “Lord of the Rings” is a similar mythic narrative, and to be honest I think the movies had a better development than Star Wars, in spite of a few deviations (fortunately rather few) from Tolkien’s novels.

There are a host of things which are likely impossible or highly implausible in Star Wars. One of course can’t predict the future, but you can extrapolate from past and current trends to make prognostications, such as we will eventually run out of abundant oil. I can’t give predictions of the oil spot market this summer, nor can I predict exactly when the peak will happen, but it will eventually. I can also use known science and logic. The warp drive is likely not physically possible, such as when Han Solo warped the Falcon away from Tatooine to the doomed Alderaan. All of the ships in Star Wars apparently had this ability, including the Death Star. The light sabers seem highly implausible, and were a theatrical device which allowed for the choreography of classic battle scenes. How can one confine energy in an invisible field-bottle which is resistant or hard? Even ray guns, blasters, phasors, and the like are unlikely, though maybe not impossible. Directed energy weapons destroy their target by imparting energy on it. A kinetic energy weapon delivers a projectile with far larger momentum which creates a material deformation and penetrates the target and systems within. A gun delivers a lethal projectile with a few grams of propellant, while a Sci-Fi ray hand held gun would require the energy of a small nuclear reactor. The nuclear bomb pumped directed X-ray pulse or beam weapon might be possible, though not desirable.

If I wanted to destroy Earth (given current or assumed technology available this century) what kind of power source would I use? How big would it need to be? What other major factors do we need to consider? For example, an equal reaction in the opposite direct such as powerful thrusters.

Could this be more easily achieved with some kind of kinetic projectile gun? I.e. enormous rail gun?

There is no way we can destroy Earth. We certainly can’t blast the planet into asteroid bits. With the best of our nuclear weaponry or another century of polluting, mining, climate heating, devastating eco-systems and so forth we will not kill off life on Earth. We can do a lot of damage, and we may in the end be engineering the 6th mass extinction, but we can’t kill off life on this planet. In 25 million years life will be doing just fine. The Prophet George Carlin has this about right:

By the time the idiot corporate CEOs, businessmen and their stooge politicians wake up to this problem it will probably be too late. Indeed I speculate that the corporate puppet-masters actually know about this, but don’t care and only care about making greater profits in the short term. Actually if we fought the global nuclear war now we might actually minimize the long term damage we do to the planet.

I doubt we humans will ever develop the technology capable of managing the energy necessary to blast Earth into bits, and I also doubt we will ever grow in our power so as to really kill of Earth-life.

As I indicated above we would have to convert 10 trillion tons of matter to energy to do what the Death Star did to Alderaan. So we would have to conjure up that much antimatter. Given our accelerator technology has over the last 40 produced about a gram of anti-matter that would take a long time. To convert this amount of matter to energy by nuclear bomb it means the bomb core would have a mass of about 10^{19} tons, or about 10 times the mass of water in the oceans. There is nothing “in principle” which says we don’t have the means, but the scale of things is so utterly beyond anything we can practically grapple with.

We might be able to scorch the Earth, burn every square kilometer of land surface, if we build a lot of nuclear bombs and detonated them at every 10km point in a grid. Around a billion 1 megaton H-bombs would about do the trick. A space based alternative would be to put a huge Fresnel lens at the L1 point. This could be about 100km in radius area. Solar radiation could then be directed in some raster scanning process to burn everything. Both of these are marginally within our abilities, or might be in the not distant future.

If you wanted to kill of all, or nearly all, human life the means are far more within our reach. The most efficient way of doing this is to design a disease which spreads rapidly and has an enormous virulence. If this could be designed up so as to infect the entire human population within a few months it could accomplish its goal before health and disease research organizations could find a cure or vaccine. As my undergraduate work was biophysics and later I worked on a genome program I can tell you that cloning genes and the like is not difficult, and the price for cloning has gone from about $25 per base pair in the late 1970s to a fraction of a penny, and the Moore’s law operates still. For around $5000 anyone can set up a fair to decent bio-lab at home, and people are designing up organisms more and more. There is a recent flap over the genetic modification of H5N1 which infects ferrets, and so the fear is this bird flu could be modified to more effectively jump to humans. This disease has a 60% lethality rate, surpassing the lethality of the black death of 1348-51. Indeed I suspect it will only be a decade or two before designed viruses which cause infections will supplant computer viruses as the high-tech annoyance of the world. Out of this might indeed come some designed virus which reduces the human population to a few million or even zero, and this could be done for a modest cost and in an average suburban home.

We might be able to scorch the Earth, […]. A space based alternative would be to put a huge Fresnel lens at the L1 point. This could be about 100km in radius area. Solar radiation could then be directed in some raster scanning process to burn everything.

In my cunning plan for World domination…
If aliens wanted to wipe out all life on Earth, the simplest method would be to place a ring of concave mirrors in polar orbit around the Earth, angled at 45° to the Sun, which would focus the Sun’s energy in a ‘ring of fire’ and eventually scorch the entire Earth’s surface, over a period of 12 hours, as it rotates on its axis.

A white persian cat. I believe this is a reference to a 007 movie, either Dr. No or Blowfat? It has been a long time since I have seen those. It has actually been a long time since I have seen any of the Star Wars movies.

Thanks kill joy. Fortunately, Lucus didn’t take into consideration plausibility when he made the movies. Furthermore, if 1,000,000 is the total knowlwedge in the universe, we are probably at around 4 right now.

“ha! anything with those capabilities would have no need to oppress anything at all.”

I see no reason to make that assumption.

I can imagine a learned person in ancient Greece or Rome saying the same thing after being told of 21st Century nuclear power, and yet here we are…

Indeed, the essence of most SF is that new technologies don’t change human motivations very much, but may give them new (and even unexpected) ways to be expressed. And the real world tends to support that.

(That, and the fact that all fiction, science or not, requires one or more people with one or more problems to solve, endure or overcome. We might want to *live* in a ‘perfect’ world, but no one wants to read a book/watch a movie about one. It’s true that theaters want to sell you popcorn…but movie studios want to sell you entertainment.)

Well, nobody said all of the planet-pieces achieved escape velocity. It could have been simple thermal shock.

On second thought though, the fragments of the (terrestrial-scale) planet seemed to have covered the diameter of the planet within a small fraction of a second. Definitely escaping…. Hell, those are relativistic speeds for the debris – I’m so glad none of them actually hit the death star. Well, not glad, conflicted.

Well ok, this may be a bit pedantic, but their assumptions are wrong and in this case it would matter.

Setting aside absurdity of a directed energy weapon having enough power to destroy a planet, there is the point that having a DEW powerful enough to destroy a planet of uniform density would not mean that it could destroy a real planet like the Earth because most of the mass of the Earth (5.5.g/cm^3 ) is in the core.

We must not forget the Dr. Who episode, “The Pirate Planet,” written by Douglas Adams. Here a giant hollow shell materializes around a planet and consumes it in order to run a time dam which keeps the queen frozen in time and immortal.

My only issue with this article is the assumption that it would strain the Death Star’s resources to destroy a planet the size of Jupiter. Is it assuming that the planet in question would be solid? After all, Jupiter is mostly gas, or is this also accounting for the core?